The development of solid block cleaning compositions has revolutionized the manner in which detergent compositions are dispensed by commercial and institutional entities that routinely use large quantities of cleaning materials. Solid block compositions offer unique advantages over the conventional liquids, granules or pellet forms of detergents, including improved handling, enhanced safety, elimination of component segregation during transportation and storage, and increased concentrations of active components within the composition. Because of these benefits, solid block cleaning compositions, such as those disclosed in Fernholz, et al., U.S. Pat. Nos. Re 32,763, Re 32,818, 4,680,134 and 4,595,520, have quickly replaced the conventional composition forms in commercial and institutional markets. Another sodium hydroxide and sodium carbonate cast solid process using substantially hydrated sodium materials was disclosed in Heile et al. U.S. Pat. Nos. 4,595,520 and 4,680,134. Further, pelletized materials are shown in Gladfelter et al., U.S. Pat. Nos. 5,078,301, 5,198,198 and 5,234,615. Extruded materials are disclosed in Gladfelter et al., U.S. Pat. No. 5,316,688. The solid block format is a safe, convenient and efficient product format.
Various hardening mechanisms have been used in cleaning and sanitizing compositions for converting a fluid composition to a solid mass for containment and modification of the solubility of the active ingredients during use. For example, the active ingredients may be combined with the hardening agent under melting temperatures, commonly referred to as a “molten process,” to achieve a homogeneous mixture, wherein the melt is then poured into a mold and cooled to a solid form.
Solid block cleaning and sanitizing compositions and detergents provide a significant improvement over the conventional liquid, granular and pelletized cleaning compositions. Although the molten process is useful for preparing solid block compositions, time and expense would be saved if heating and cooling of the composition could be minimized or eliminated from the process, and higher viscosities could be used. Also, lower process temperatures would better facilitate the use of heat-sensitive ingredients in cleaning compositions. In addition, less sturdy packaging would be required if the processed mixture could be packaged at a lower temperature. Furthermore, eliminating molten temperatures would avoid swelling and deformation of the solid product.
Various attempts have been made to manufacture cleaning compositions by an extrusion process. U.S. Pat. No. 5,061,392 to Bruegge et al., for example, discloses a method of forming a detergent composition having a paste-like consistency, by combining a first aqueous solution containing a potassium tripolyphosphate and a second aqueous solution containing a water-soluble, sodium-based detergent builder, namely sodium hydroxide. Upon mixing, the viscosity of the mixture rapidly increases to form a highly viscous paste. In another extrusion method, as disclosed in U.S. Pat. No. 4,933,100 to Ramachandran, an organic detergent of particulate or patty form is formed by kneading together a synthetic organic detergent, a hydratable builder salt such as sodium tripolyphosphate, and water. The mixture is passed through an extruder and forced through openings at or slightly above room temperature and a low pressure to form a rod-shaped extrudate. A disadvantage of these processes is that a caustic, hydratable alkaline source is required to facilitate hardening of the processed composition after extrusion.
As can be seen there is a need in the art for development of cleaning composition which can be formed into solids by less involved processes such as by pressing. Aqueous cleaning compositions have commonly been used in applications including hospital, household, institutional and industrial services, hand and body soaps, laundry soaps, warewashing and housekeeping surfaces. Typically, these cleaning materials are made by diluting liquid or gelled materials to form a use solution. Many such solutions have had some success in the past, however, a substantial need in this art exists to manufacture an easily used concentrate having minimal water and a high actives concentration, excellent soil, e.g. grease, removal properties and controlled foaming. Many prior art materials even in a concentrate form contain substantial amounts of water which is difficult to manufacture, transport and sell. The materials also may have some soil removal properties but improving grease removal and hard surface cleaners is a continuing need or requirement. Further, the manufacture of materials that produce useful foam in the presence of large quantities of greasy soil is a continuing challenge for this marketplace.